Research Highlights Featured Chart

January 22, 2026

Technological change and the transformation of women's work in the twentieth century

The adoption of milking machines in Norway.

Tyler Smith

Source: sauletas

The introduction of milking machines to Norwegian dairy farms in the 1950s eliminated one of the most common occupations performed by rural women. In a paper in the American Economic Review, authors Philipp Ager, Marc Goñi, and Kjell G. Salvanes tracked approximately 725,000 Norwegians, using detailed registry data to document how this technological shock affected men and women in rural areas.

When Norway lifted import restrictions on agricultural equipment in 1951, the adoption of milking machines accelerated rapidly, but unevenly, across the country. By comparing municipalities with different levels of adoption, the researchers were able to determine the impact of the technology shock on economic outcomes.

Hand milking was almost exclusively women's work. In dairy-intensive municipalities, young unmarried women, aged 16 to 25, typically worked as milkmaids before marriage, whereas men on farms generally worked outdoors. 

Figure 4 from the authors’ paper tracks the relative income trajectories of women and men from different municipalities who turned 16 in 1970, following them for 25 years.

Figure 4 from Ager et al. (2025)

Panel A shows the effect on women's income percentile rank relative to municipalities with lower adoption of milking machines in 1970. During the first five years, women from areas with high adoption experienced income declines of 4 to 13 percentile ranks per each additional milking machine per farm. However, a reversal begins around year 15, and, by 20 to 25 years after the technology shock, women from high-adoption municipalities consistently ranked higher in the income distribution than their counterparts from areas with fewer machines. 

Panel B demonstrates that this reversal was gender-specific. The gap between women's and men's income trajectories widened over time, with women gaining approximately 5 percentile ranks relative to men by the end of the observation period.

The authors argue that this long-term improvement resulted from geographic mobility and educational investment. Displaced young women migrated to urban areas at higher rates than men, where they were more likely to obtain undergraduate degrees and move into higher-skilled positions, particularly in Norway's expanding service and public sectors.

The experience of Norwegian milkmaids suggests that gender-biased technological shocks can narrow the gender gap by disrupting entrenched gender norms in the labor market.